My horse is a 17 year old quarter horse. I barrel race him and lately his knees have started to seem as if he can't support himself fully, but it's an on and off thing, such as last weekend it was like that, and today he was fine. Whenever I ride him it has no effect
on him whatsoever and he still wants to run. I'm going to put him on joint support and my friend recommended Senior feed. Any other recommendations?